The present invention relates to gas burners, and, in particular, it embraces the intermixing or "intersection", within a fire chamber, of a substantially vertical flow of flammable fluid with a substantially vertical stream of secondary air to produce an aesthetically appealing yellow flame which burns efficiently and cleanly.
Gas fireplaces are rapidly replacing wood burning fireplaces. In general, they are easier to clean, easier to maintain and cleaner burning than conventional wood burning fireplaces. Commonly, "primary air" is introduced into a gas-air mixing chamber so as to achieve more complete combustion. However, this requires the use of a mixing chamber which adds to the cost and complexity of the unit. A common drawback of gas fireplaces is that they have difficulty in producing a flame which resembles that of a natural wood log fire. Further, those gas fireplaces which have been able to produce a yellow flame produce high amounts of carbon monoxide and other undesirable pollutants.
U.S. Pat. No. 4,838,240, and U.S. Pat. No. 4,838,241, both to Rieger, disclose a burner assembly for use in a fireplace. The burner assembly produces a flame pattern which resembles that of a natural wood log fire and has a reduced level of carbon monoxide production. The flame is yellow. Gas enters the burner assembly through an orifice and mixes with a predetermined amount of fresh air in a mixing chamber. The mixture of gas and air is transferred to an opening to be lighted. A problem with Rieger is that it requires a mixing chamber which adds to the cost and expense of manufacture.
U.S. Pat. No. 3,947,229 to Richter discloses an artificial fireplace having a burner and simulated logs. The burner includes a chamber for the mixing of gas and air. The mixture of gas and air passes through a myriad of tiny passageways and is then ignited. A problem with Richter is that it requires both a mixing chamber and a myriad of passageways for the gas-air mixture. This adds to the complexity and cost of the unit.
U.S. Pat. No. 2,084,566 to Warfield discloses a gas fireplace log. The log is hollow and receives a mixture of gas and air through a mixing tube. The mixing tube receives air from an inlet aperture and gas from a gas line. The mixing tube leads to a burner within the hollow log. Burning occurs completely within the log. A drawback of Warfield is that it requires a mixing tube and a hollow log. Thus, the cost of manufacture is increased.
U.S. Pat. No. 3,760,790 to Voges et al. broadly discloses that it is known to mix secondary air with a gas at the base of a flame but does not disclose how this is done. A problem with Voges, however, is that the air is not introduced vertically into the root or base of the flame. Hence, the height of the flame may only be adjusted by varying the flow rate of the gas or varying the size of the gas orifice.
Accordingly, none of the related art describes a method and/or apparatus for producing a clean burning yellow flame involving the intersection, within a fire chamber, of a substantially vertical flow of flammable fluid with a substantially vertical flow of secondary air wherein the height of the flame may be varied by varying the rate of introduction of the vertical flow of secondary air.
It is therefore an object of the present invention to significantly reduce the amount of carbon monoxide and other pollutants produced by an aesthetically appealing yellow flame.
It is another object of the present invention to produce an aesthetically appealing, clean burning yellow flame without the use of mixing chambers and/or mixing tubes.
It is a further object of the present invention to vary the height of an aesthetically appealing clean burning yellow flame by varying the rate of introduction of secondary air and/or varying the rate of introduction of gas.